Based on the current physical interference model of wireless networks such as ultra wide band (UWB) ad hoc networks, the number of concurrent transmission of signals by nodes within a wireless network are strictly limited by the topography (i.e., density and locations of the nodes) of the ad hoc wireless network and the maximum signal transmission ranges of the nodes. As used herein “ad hoc networks” may refer to any type of wireless networks including, for example, personal area networks (PANs), wireless local area networks (WLAN), and so forth. Some of the limitations of the current physical interference model of wireless networks are illustrated by the following example.
Consider a wireless network having six nodes, A, B, C, D, E, and F located at different geographical locations. When one of the nodes, node A, is to transmit data packets to another node, node B, nodes within the areas covered by the transmission ranges of nodes A and B will not be allowed to transmit and/or receive messages to or from other nodes, depending upon the location of node in the area covered by the transmission ranges of nodes A and B. The area covered by the transmission range of transmitting node A may be referred to as reception exclusive space (RES), whereas the area within the transmission range of receiving node B may be referred to as the transmission exclusive space (TES). The area within the intersection of the RES and TES may be referred to as the communication exclusive space (CES).
So, when node A is transmitting data packets to node B, any node within the RES will not be allowed to receive signals from other nodes of the wireless network, while any node within the TES will not be allowed to transmit signals to other nodes of the wireless network. Further, when node A is transmitting data packets to node B, any node within the CES (i.e., other than nodes A and B) will not be allowed to either transmit or receive signals from other nodes.
So if nodes C and E are located in the RES and TES respectively, nodes C and E are limited, at least in part, from fully communicating with other nodes of the wireless network, when node A is transmitting data packets to node B. That is, when node A is transmitting data packets to node B, node C, in RES, may not receive signals from, e.g., node D, even if node D is proximally located near node C outside the RES. However, node C may transmit signals to node D. In contrast, node E may not transmit signals to, e.g., node F, even if node F is proximally located near node E outside the TES. But, node E may receive signals from node F.
Because of the relatively large exclusive spaces that are needed under the current physical interference model, the overall data throughput of the wireless network is very limited, particularly if the network is densely populated with nodes.